Enantioselective synthesis of polycyclic ketones by desymmetrisation of bis(phenylsulfonyl)alkenes with chiral alcoholates. Control of the absolute configuration by a simple modification of the chiral auxiliary

1999 ◽  
Vol 40 (49) ◽  
pp. 8705-8709 ◽  
Author(s):  
Sergio Cossu ◽  
Ottorino De Lucchi ◽  
Paola Peluso ◽  
Raffaella Volpicelli
2020 ◽  
Vol 23 (26) ◽  
pp. 2960-2968
Author(s):  
Renáta Kertiné Ferenczi ◽  
Tünde-Zita Illyés ◽  
Sándor Balázs Király ◽  
Gyula Hoffka ◽  
László Szilágyi ◽  
...  

The reported enantioselective synthesis for the preparation of (+)-(2R,3R)-2-(4- hydroxy-3-methoxyphenyl)-3-hydroxymethyl-1,4-benzodioxane-6-carbaldehyde, precursor for the stereoselective synthesis of bioactive flavanolignans, could not be reproduced. Thus, the target molecule was prepared via the synthesis and separation of diastereomeric O-glucosides. TDDFT-ECD calculations and the 1,4-benzodioxane helicity rule were utilized to determine the absolute configuration. ECD calculations also confirmed that the 1Lb Cotton effect is governed by the helicity of the heteroring, while the higher-energy ECD transitions reflect mainly the orientation of the equatorial C-2 aryl group.


2021 ◽  
Author(s):  
Eryn Nelson ◽  
Jeffrey S. S. K. Formen ◽  
Christian Wolf

The widespread occurrence and significance of chiral compounds does not only require new methods for their enantioselective synthesis but also efficient tools that allow rapid determination of the absolute configuration,...


2014 ◽  
Vol 69 (11-12) ◽  
pp. 1088-1096 ◽  
Author(s):  
Jan-Niklas Schäckermann ◽  
Thomas Lindel

Abstract The first enantioselective synthesis of a photoreactive (R)-β-phenylalanine is described. In the key step, m-diazirinyl-substituted benzaldehyde is converted to a chiral sulfinimine in a Ti(OEt)4- mediated reaction, followed by diastereoselective enolate addition. The absolute configuration of photo (R)-β-phenylalanine was confirmed by Mosher analysis. The photo amino acid proved to be thermally stable under standard laboratory conditions. Irradiation in toluene afforded cycloheptatriene=norcaradiene valence tautomers, together with carbene benzylation. Quantumchemical calculations indicate a small triplet-singlet gap.


1991 ◽  
Vol 32 (35) ◽  
pp. 4505-4508 ◽  
Author(s):  
Toshio Suzuki ◽  
Ohki Sato ◽  
Masahiro Hirama ◽  
Yoshinori Yamamoto ◽  
Michio Murata ◽  
...  

2002 ◽  
Vol 13 (13) ◽  
pp. 1411-1415 ◽  
Author(s):  
Giuliana Cardillo ◽  
Serena Fabbroni ◽  
Luca Gentilucci ◽  
Massimo Gianotti ◽  
Rossana Perciaccante ◽  
...  

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